Arch Neuropsychiatr 2015; 52: 89-94 • DOI: 10.5152/npa.2015.7169
Reliability and Validity Study of the Turkish Version of the Clinical Opiate Withdrawal Scale A. Ender ALTINTOPRAK1, E. Cüneyt EVREN2, Ömer AYDEMİR3, Aslıhan YAPICI ESLEK4, Yeşim CAN2, Elif MUTLU2, Levent TOKUÇOĞLU5, Artuner DEVECİ3, Hakan COŞKUNOL6 Department of Psychiatry, Ege University Faculty of Medicine, İzmir, Turkey Bakırköy Prof. Dr. Mazhar Osman Psychiatric Training and Research Hospital, AMATEM, İstanbul, Turkey 3 Department of Psychiatry, Celal Bayar University Faculty of Medicine, Manisa, Turkey 4 Manisa Psychiatric Training and Research Hospital, AMATEM, Manisa, Turkey 5 Freelance Psychiatrist 6 Ege University. Institute on Substance Use, Toxicology and Pharmaceutical Science, İzmir, Turkey 1 2
ABSTRACT Introduction: The aim of the present study was to perform reliability and validity analyses of the Turkish version of the Clinical Opiate Withdrawal Scale which is used to determine the severity of opiate withdrawal. Methods: Initially, the Clinical Opiate Withdrawal Scale (COWS) was translated into Turkish and subsequently back-translated into English. The originality of the back-translated version was approved by the author who developed the scale. After the translation was completed, the scale was used to assess the withdrawal symptoms of 100 patients with opiate withdrawal and 41 patients with alcohol withdrawal. Cronbach’s alpha was used in the reliability assessment; explanatory and confirmatory factor analyses were used in structural validity assessment; and in scale validity, ROC analysis was used among diagnosis groups.
Results: The Cronbach’s alpha internal consistency coefficient was calculated as 0.74 in reliability analyses. The correlation coefficient was found to be 0.975 (p36 are regarded as severe withdrawal symptoms. The scores of these categories are because of the author’s clinical experience and were not determined by using standard statistical methods (1). Statistical Analysis In the statistical assessment, initially, analysis of the variance test (ANOVA) was applied to quantitative variables, and the chi-square test was applied to categorical variables in terms of socio-demographic and clinical properties among research groups. In the reliability analyses, a Cronbach’s alpha internal consistency analysis was conducted for the scale. In addition, item-total score correlation coefficients were used to investigate the reliability of the scale. To control for inter-rater reliability, the correlation coefficients of the scores given by the two examiners who had passed through similar training procedures were used. In the reliability analysis, the test re-test method was not chosen because opiate withdrawal is a rapidly changing clinical manifestation. The split-half method, which is another reliability analysis, was not chosen either. However, a split half consistency is not expected because the scale does not have homogenous items. Explanatory and confirmatory factor analyses were used in the construct validity of the scale. An explanatory factor analysis was conducted by applying a varimax rotation according to the principal components method, and factors whose eigenvalues were ≥1 were included in the assessment. Items with factor loads equal to ≥0.4 in their factor structures were evaluated. Explanatory factor structure was compared with the original one-dimensional structure of the scale. In the confirmatory factor structure, when evaluating the scale’s compatibility with the one-dimensional model and stability model of the data, different types of “goodness-of-fit” indices were used with the maximum probability method. These included the following: root mean square error of approximation (RMSEA), goodness-
Arch Neuropsychiatr 2015; 52: 89-94
of-fit index (GFI), and comparative fit index (CFI). RMSEA is an absolute index of fit. RMSEA values 0.10 indicate an unacceptable fit. The CFI and GFI values may change between 0 and 1 and should be >0.90. Another characteristic of CFI is that it is least affected by problems in sample size and distribution. A receiver operating characteristic (ROC) analysis was performed between the opiate and alcohol withdrawal groups to detect scale validity of COWS. Moreover, the COWS total score was compared among two research groups with a t-test.
RESULTS The research was completed with 141 participants, 100 of them diagnosed with opiate withdrawal and 41 of them diagnosed with alcohol withdrawal. Fifty-five opiate and 20 alcohol-dependent patients were recruited from Bakırköy AMATEM, 30 opiate and 15 alcohol-dependent patients from Manisa AMATEM, and 15 opiate and 6 alcohol-dependent patients from Ege University. Socio-Demographic Characteristics Socio-demographic and clinical characteristics of the participants are given in Table 1. The opiate withdrawal group is younger than the alcohol withdrawal group (t=−7.80, p